An acoustic structure includes a plate and at least one acoustic scatterer having a resonant frequency and coupled to a side of the plate. The at least one acoustic scatterer has an opening, a first channel and a second channel. The first channel has a first channel open end and a first channel terminal end with the first channel open end being in fluid communication with the opening. The second channel has a second channel open end and a second channel terminal end with the second channel open end being in fluid communication with the opening. The first channel terminal end and the second channel terminal end are separate from one another.